Research on smart wearable devices that are compact and light to be equipped on a body and have improved convenience is being very actively conducted. Samsung Electronics, Apple, Google, Nike, Adidas and so forth are representative companies that have researched in earnest to launch innovative products.
Google presented a smart watch after Google Glass 2.0, and recently has attracted new attention with the development of a smart contact lens. Likewise, many global research companies are developing a variety of electronic devices to diagnose and treat human diseases, keeping up with the development of e-health systems. Also, for more convenient treatment of a disease and regular injection and drug administration, a diagnosing system capable of simply controlling a drug delivery system using a smartphone has been developed.
Generally, glasses are used for vision correction or eye protection from the sun. Currently-presented special glasses are Google Glass developed by Google-X manufactured by incorporating an electronic device into glasses for real life convenience, Recon Jet developed by Recon, and electronic glasses that are developed by Epson, Lumus, Vuzix, Oakley, Laster, Olympus, Digilens, Microsoft Fortaleza and Sony. Such special glasses can be used to take a photograph or record a video or audio, and show a specific screen. However, such special glasses are too large and heavy to be used for a long time, and thus are inconvenient. The latest special glasses are Google Glass that uses optical head-mounted display (OHMD) technology. While the Google glass is a pair of multi-functional special glasses having various functions, it consumes high power, has a slow display conversion rate and is very expensive, and therefore it is disadvantageous to be used generally.